The present disclosure relates to a method for producing a positive electrode of a thin-film battery and a method for producing a thin-film battery. More specifically, the present disclosure relates to a method for producing a positive electrode of a thin-film lithium-ion secondary battery and a method for producing a thin-film lithium-ion secondary battery.
Due to the remarkable developments of mobile electronic technology in recent years, mobile electronic devices such as cellular phones and notebook-type personal computers have come to be recognized as a basic technology supporting the advanced information society. Furthermore, research and development relating to the sophistication of such devices have been actively performed and, in proportion to this, the power consumption of mobile electronic devices has continuously increased. However, such electronic devices are required to operate for a long time, which necessarily demands an increase in the energy density of secondary batteries serving as operation power supplies.
In view of the occupied volume, weight, and the like of batteries contained in mobile electronic devices, the higher the energy density of the batteries is, the more desirable it is. Lithium-ion secondary batteries using doping and dedoping of lithium ions have excellent energy density and hence are widely used for mobile electronic devices.
Among lithium-ion secondary batteries, in thin-film lithium-ion secondary batteries in which the batteries are formed by using the thin-film technology, a further decrease in size and weight can be achieved. Thus, thin-film lithium-ion secondary batteries are expected as power sources for IC cards and small electronic devices.
For example, a thin-film lithium-ion secondary battery described in Japanese Unexamined Patent Application Publication No. 2006-216336 has a configuration in which a positive-electrode collector layer, a positive-electrode active material layer, a solid-electrolyte layer, a negative-electrode active material layer, and a negative-electrode collector layer are stacked on a substrate. As a method for forming the layers (thin films), a sputtering method, CVD, a vacuum deposition method, an electron-beam deposition method, laser ablation, a sol-gel process, or the like is used.
However, thin-film lithium-ion secondary batteries obtained by conventional production methods have a problem of poor utilization efficiency of the positive electrodes.
Accordingly, an object of the present invention is to provide a method for producing a positive electrode of a thin-film battery and a method for producing a thin-film battery in which the utilization efficiency of the positive electrodes can be enhanced.